Trails should include a generator-trails test

[jaumard]

When a PR is made on Trails, it could be nice to have a unit test who test if the generator-trails generate a working project.

Like this if a file is removed or added the generator-trails can test if it able to generate a working project or not.

[tjwebb]

Cool, we should add that to the smokesignals ecosystem CI script: https://github.com/trailsjs/smokesignals/blob/master/bin/ci.js